Siegecrafter Blackfuse Detailed Strategy Guide (Heroic Mode included)

This guide is intended to provide a comprehensive description of the
encounter with Siegecrafter Blackfuse in Siege of Orgrimmar. It is targeted at anyone
who desires to understand the fight mechanics.

This guide is updated for World of Warcraft WoD 6.1.2.

Siegecrafter Blackfuse is the twelfth boss in the Siege of Orgrimmar. This
is an extremely complex encounter, during which your raid will have to not
only fight against Blackfuse, but also contend with a large number of the boss'
gadgets and devices.

The encounter against Siegecrafter Blackfuse is a single-phase fight.
Your raid will face not only Blackfuse himself, but also several types of
adds.

There are two conveyor belts, one located at each end of the room where you
fight Blackfuse. At regular intervals throughout the fight, several inactive
adds will be brought it on the north-western conveyor belt. Your raid members
can move up on the conveyor belt and attack these adds, but only one
can be killed, as the remaining ones become immune when one dies. Soon after
that, any adds that were not killed will appear on the north-eastern
conveyor belt, where they cannot be attack, and from where they use their
abilities against your raid for a certain amount of time.

Videos:

PTR Preview —
a short overview of the boss, based on PTR testing, which is extremely
useful for getting a rough understanding of the fight.

Video Guide
— a video guide of the boss, based on live-realm experience.

On our forums, we are maintaining threads with class-specific advice for each of the
fights of Siege of Orgrimmar. So, make sure to check them out, and if you have things to
share, do not hesitate to contribute!

5.1. Room Layout

Your raid starts out the fight on a large circular platform, located within
a much larger room. This platform is where Siegecrafter Blackfuse is
located, and it is surrounded by lava. Most of your raid will be
confined to this platform for the duration of the fight, where you will fight
Blackfuse and some of his adds.

5.2. Conveyor Belts

There are two conveyor belts in the room, located alongside the
north-western and north-eastern walls respectively. Because of the lava,
players cannot run or jump up onto these conveyor belts, but the north-western
conveyor belt can still be accessed despite the lava. Players can reach this
conveyor belt through a system of transport pipes (a la Super Mario).
These pipes are located on the platform, next to the conveyor belt, and
players can simply jump inside the pipes in order to be transported to the
conveyor belt.

Players who use the transport pipes are debuffed with
Pattern Recognition, which prevents them from using the pipes to get to
the conveyor belt for 60 seconds. There are two pipes, but there does not
seem to be any limit to the number of different players who can use the pipes,
or who can be on the conveyor belt at the same time.

On the conveyor belt itself, several things happen.

Several damaging beams of fire, called Matter Purification Beams,
are located along the belt. Coming in contact with them deals a massive amount
of Fire damage to players, but because of the way in which they are positioned,
they can be avoided.

The conveyor belt is constantly moving forward, and this also causes
players to move forward along with it. Players can "run against the current",
so to speak, in order to slow the rate at which they are moving, and to
prolong the time they can spend on the belt.

Several adds come out onto the conveyor belt. We discuss these adds in
a specific section, but for now we will mention that
they are harmless, and that your raid members can kill an add of their choice,
the remaining ones becoming immune when one dies.

When players are ready to leave the conveyor belt, they can do so by
jumping into a similar set of pipes, located at the other end of the conveyor
belt, which take players back to the platform. The Pattern Recognition debuff
has no interaction with this set of pipes.

6.1. Siegecrafter Blackfuse

Electrostatic Charge is a damaging ability that Blackfuse regularly
uses on his tank. It deals a large amount of Nature damage, and applies a
stacking debuff on the target. The debuff increases damage taken from
Electrostatic Charge by 100% per stack, but also causes the player to deal
200% increased damage to any targets that have Reactive Armor (one of the
adds has this buff). This ability requires a tank switch.

Protective Frenzy is a buff that Blackfuse gains whenever one of his
adds is killed. It lasts for 10 seconds, and it increases his attack speed by
100%.

Launch Sawblade is an ability that Blackfuse uses every 10 seconds or
so. It creates a sawblade (a sharp blade that spins in place) at the location
of a random raid member. The sawblades deal massive Physical damage to any
players who come in contact with them, knocking them back. The sawblades also
damage one type of adds, called Automated Shredders, when these come in
contact with them. The sawblades last indefinitely, but one of the adds has an
ability that removes them (although your raid must perform a certain action for
this to happen).

Energized Defensive Matrix is a buff that Blackfuse gains if your raid
fails to kill any of the adds that spawn in one wave on the conveyor belt.
This buff lasts for 20 seconds, and it reduces the damage Blackfuse takes by
90%.

6.2. Adds

6.2.1. Automated Shredders

30 seconds after the start of the fight, and roughly every 2 minutes after
that, Blackfuse summons an Automated Shredder add. These large adds
have several abilities.

Death From Above is an ability that the Shredder uses regularly. It
leaps up into the air and then lands, dealing a massive amount of Physical
damage to players in a 15-yard radius. After landing, the Shredder is stunned
for 5 seconds, during which time it takes 200% increased damage.

Overload is a raid-wide damaging spell that the Shredder regularly
uses. It deals a large amount of damage, and causes the Shredder to gain a
permanent stack of a buff increasing its damage done by 30%. Players on the
conveyor belt are not damaged by Overload.

It is worth noting that the Automated Shredders can be damaged by
Blackfuse's sawblades, as well as by several other add abilities (listed
below).

6.2.2. Conveyor Belt Adds

Every 40 seconds, a new wave of adds will enter the fight on the
north-western conveyor belt. Three different adds will enter the fight each
time, chosen randomly out of four total types of possible adds.

When on this north-western conveyor belt, the adds are deactivated
or, in the case of one of them, disassembled. Essentially, this means
that they do not do anything and they can simply be attacked and killed,
although as we have mentioned, once one of the three adds on the conveyor belt
dies, the other two become immune.

The adds that are not killed come out on the north-eastern conveyor belt
a few seconds later. Once there, they are no longer deactivated, and are
instead activated. Once on the north-eastern conveyor belt, the adds
can no longer be killed. These adds remain on the north-eastern conveyor belt
long enough to cast their ability once (they each have a single ability, and
after using it they disappear). The exception to this rule are certain
mine-like adds that jump down on the platform and need to be killed.

Below, we list the abilities of each of the four types of adds, as well as
the name of the adds when they are on the north-western conveyor belt.

Shockwave Missile creates three damaging waves of "seismic energy".
The first wave strikes a small area around Siegecrafter Blackfuse, with
subsequent waves, each about 15 yards wide, striking farther and farther out,
until the edges of the platform are reached. Each wave has an orange warning
animation that gives players about 2-3 seconds to move out of the affected
area. Players standing in an area that is affected by a wave take a very high
amount of Nature damage. Automated Shredders also take damage from
Shockwave Missile. After one cast of Shockwave Missile, the Missile Turret
despawns from the north-eastern conveyor belt.

Superheated is a laser beam that follows a random raid member,
leaving damaging void zones at the point of impact. Players who stand in these
void zones gain a stacking DoT that deals a small amount of Fire damage per
second for 7 seconds. Automated Shredders also take damage from
Superheated void zones. After chasing a player with the laser beam for 10
seconds, the Activated Laser Turret despawns.

Magnetic Crush pulls all players and sawblades towards the
Activated Electromagnet over the course of about 10 seconds. Players can
resist this effect by running in the opposite direction, but all the sawblades
will inevitably make their way to the Activated Electromagnet, being removed
from the fight. Any players or Automated Shredders who come in contact with
sawblades that are being pulled by an Activated Electromagnet take damage from
them. After one cast of Magnetic Crush, the Activated Electromagnet will
disappear.

Several Crawler Mines jump down from the north-eastern conveyor
belt, fixating on random raid members and moving towards them.

When a Crawler Mine reaches its target, it casts Detonate!,
self-destructing and dealing a large amount of Fire damage to all raid
members, knocking them up in the air.

For the first minute after spawning, the Crawler Mines are debuff with
Break-in Period, which renders them vulnerable to root, snares, and
stuns. After 1 minute, Break-in Period is replaced by Ready to Go!, which
removes the previously-mentioned vulnerability and increases the Mines'
movement speed.

We will first summarise the strategy for the fight, before going into
more details in subsequent sections.

Have your tanks perform a tank-switch on Siegecrafter Blackfuse and
the Automated Shredders, while making sure to keep the boss at least 35
yards away from any adds to avoid them being healed. The Automated Shredder
tank will be killing this add.

Assign certain players to go to the north-western conveyor belt each time
a new wave of adds spawns there, and have them kill one of the three adds in
the wave.

DPS Blackfuse while avoiding the damage from the adds, including those
adds that enter the fight on the north-eastern conveyor belt.

7.1. Tanking

The ideal location to tank Blakfuse in is at the edge of his platform, right
next to the north-western conveyor belt. Tanking the boss at the edge
means that the waves from Shockwave Missile will be easier to avoid, and
tanking him at this particular edge gives your raid the greatest possible
distance from where the Crawler Mines spawn (they spawn next to the
north-eastern conveyor belt).

Blackfuse's tank cannot also tank the Automated Shredders, since they
would be healed by the Automatic Repair Beam aura if they were to come
within 35 yards of the boss. This means that Blackfuse and the Automated
Shredders must be tanked by different tanks, who must always be at least 35
yards apart.

A tank switch must be performed on Blackfuse, due to the
Electrostatic Charge debuff. Normally, the damage that a tank debuffed
by Electrostatic Charge does to the Automated Shredder should kill it by the
time the next Shredder spawns, meaning that your tanks can switch their targets
without fear of bringing Shredders too close to Blackfuse (since they would
switch when no Shredders are up, and the tank who does not have Blackfuse can
pick up the new Shredder when it spawns afterwards).

Blackfuse's tank will have to be prepared with a defensive cooldown whenever
an add dies, since the boss buffs himself with Protective Frenzy when
this happens.

The Automated Shredder tank must watch out not be get hit
by the add when it casts Death From Above. Also, it is somewhat useful
to have the Automated Shredders take damage from the various add abilities
that damage them, but this is certainly not mandatory.

7.2. Conveyor Belt Assignments

A new wave of adds spawns on the north-western conveyor belt every 40
seconds, but due to the Pattern Recognition debuff, any one player can only
travel to the conveyor belt every 60 seconds. This means that you will need to
assign two different teams to handle the conveyor belt alternatively.

Players on the conveyor belt do not take any damage (unless they fail to
avoid the Matter Purification Beams, in which case they die anyway), so
there is no need to send any healers there. There is no need for tanks, either,
so you should only assign DPS players to the conveyor belt.

In 10-man, it is enough to send 2 DPS players to the conveyor belt to
assure that the desired add is killed before reaching the end of the belt. In
25-man, 4 players will do the job.

Finally, there is the question of which add your raid should kill on the
north-western conveyor belt. There is no simple answer, since each raid group
may have difficulty with different abilities, based on its strengths and
weaknesses. That said, we believe that you should mostly kill the
Disassembled Crawler Mines, since they are the most disruptive to your
raid. You will have to regularly (at least once every 3 waves) allow
a Deactivated Electromagnet to make it over to the north-eastern conveyor
belt, since you need this add's Magnetic Crush to remove the sawblades
from the room.

7.3. Main Platform

On the main platform, your raid members will have to essentially DPS
Siegecrafter Blackfuse while surviving the many abilities used by the boss
and the adds.

Your raid members will have to stay away from any
sawblades that Blackfuse creates through Launch Sawblade. These sawblades
will limit the amount of space your raid has, so that is something you will
have to account for. Whenever an Activated Electromagnet casts
Magnetic Crush, make sure that you are not standing between the
Electromagnet and any sawblades, since they will hit you when they come in
contact with you.

Players will have to avoid being hit by
Automated Shredders when they cast Death From Above. The
Automated Shredders' Overload simply requires that your healers
react accordingly to the raid damage. The damage of the Shredders increases the
longer they are alive (since their damage increases each time they cast
Overload), but this should not be a problem as long as your tanks perform the
tank switches correctly.

Next, your raid members will have to handle the Activated Laser Turrets
intelligently. Players who are targeted by the laser beam, and who are
therefore leaving behind Superheated void zones must take the beams in
areas where they will not interfere with your raid's positioning, and they
must especially pay attention to the current location of the sawblades.
Specifically, it is important not to lock players in between sawblades and
Superheated void zones.

A particularly difficult part of the fight is when Crawler Mines
jump on the platform. Players who are fixated upon by these adds must kite
them around, and they must be killed before they reach their targets. Your
raid should take advantage of the Break-in Period debuff that the Crawler
Mines have for the first minute after they spawn, and stun, snare and root them
while killing them quickly. Even though the Crawler Mines have low health, it
is still important not to kite them next to Siegecrafter Blackfuse, since his
Automatic Repair Beam will heal them.

Finally, your raid will have to avoid the damage caused by the
Activated Missile Turrets' Shockwave Missile. Given the fact that each
wave gives players ample time to avoid it, this ability is not really very
problematic. If players stand about 15 or 30 yards away from Blackfuse when
this ability is about to be cast, then they should be very close to the edges
of the waves. We would also note that Hunters' Deterrence works to
prevent damage from this ability.

We recommend using Heroism/Bloodlust/Time Warp at the
start of the fight, to benefit from the fact that all your raid members' DPS
cooldowns are available, and also because no other more suitable moment exists
throughout the fight.

In this encounter, your raid will be under a lot of pressure right from
the start, with many abilities being used against you all at once. Since most of
these abilities require awareness and good reflexes in order to be avoided,
you will have no choice but to pull the boss as many times as it is needed for
all raid members to get used to these abilities.

As a raid leader, you should look to see which of the adds that comes in on
the north-western conveyor belt is most difficult for your raid to deal with
and have that one killed each time.

The Heroic mode of the Siegecrafter Blackfuse encounter is heralded as
one of the most difficult Heroic modes of the instance, arguably more difficult
than most fights that precede it. While there are not many changes to mechanics
(and practically no entirely new mechanics), the execution of the fight is
very challenging.

11.1. Differences From Normal Mode

All the mobs in the fight have increased health, and their abilities and
melee attacks deal increased damage.

In addition to this, the biggest change to the fight comes in the form of a
buff that is applied to one of the weapons that survive each wave on the
north-western conveyor belt. One of the surviving weapons will become
Overcharged, which means that when it re-appears on the north-eastern
conveyor belt, its mechanics will be different (more dangerous). We will go
through each of the different weapons' Overcharged states below.

Overcharged Electromagnets now alternate pulling and pushing players
and sawblades, instead of simply pulling them to the magnet. This back-and-forth
continues while the Electromagnet is active, but before it despawns it will
still remove all of the sawblades, as in its non-Overcharged version.

Overcharged Crawler Mines now spawn two larger Crawler Mines in
addition to some regular, small ones. The large Crawler Mines act exactly like
the smaller ones, except that when they die, they split up into two small
Crawler Mines each.

Overcharged Missile Turrets now successively summon three Missile
Turret NPCs on the platform, instead of casting Shockwave Missile.
Each of these NPCs will cast Shockwave Missile continuously until it is killed. When one Missile Turret is killed, the next one spawns (new Missile Turrets
always spawn to the right of the previous one, when looking towards the
outside of the platform), until you have killed all 3 turrets.

Overcharged Laser Turrets no longer follow a player with a laser beam,
but instead they now create three concentric rings of fire on the floor of the
platform. These rings of fire do not touch, however, leaving several
safe areas for raid members (the very center of the platform, the outer edge,
as well as another safe ring around half-way between the center and the
edge).

There are two rules that govern the Overcharging of weapons. The first is
that Overcharging is done based on a priority system, which is as follows:

Electromagnet

Crawler Mines

Missile Turret

Laser Turret

The second rule is that the same weapon cannot become Overcharged twice in
a row.

There is one other small change to the mechanics of the fight. On the
north-western conveyor belt, the walls formed by the
Matter Purification Beams no longer have a fixed gap in them. Rather, the
gap regularly changes position, as one of the beams is always inactive. Each
inactive beam is only inactive for a very short time (about 5 second), after
which time it immediately re-activates and a new beam deactivates.

11.2. Strategy

While the overall strategy of the fight does not change, several small
aspects of it do differ in Heroic mode.

The most important aspect of the Heroic mode strategy is properly dealing
with the Overcharged versions of the weapons. Your raid can determine the
order in which the weapons will overcharge, to an extent, since the
composition of each wave of weapons on the conveyor belt is fixed. We will
list the compositions of all 12 waves below (wave 13 marks the enrage timer of
the fight).

Wave 1: Crawler Mines, Missile Turret, Laser Turret

Wave 2: Crawler Mines, Missile Turret, Laser Turret

Wave 3: Electromagnet, Missile Turret, Laser Turret

Wave 4: Crawler Mines, Missile Turret, Laser Turret

Wave 5: Electromagnet, Crawler Mine, Missile Turret

Wave 6: Crawler Mines, Crawler Mines, Laser Turret

Wave 7: Crawler Mine, Missile Turret, Laser Turret

Wave 8: Electromagnet, Crawler Mines, Missile Turret

Wave 9: Crawler Mines, Laser Turret, Laser Turret

Wave 10: Crawler Mines, Missile Turret, Laser Turret

Wave 11: Electromagnet, Missile Turret, Missile Turret

Wave 12: Crawler Mines, Electromagnet, Laser Turret

Enrage

Note that within each wave that has the same composition, the order in which the weapons enter the conveyor belt is different, but this is not really
relevant.

Knowing that the weapons to be Overcharged are chosen based on a fixed
priority system, it is possible, to an extent, to control what weapon will
Overcharge next. We recommend that each raid creates a strategy that
minimises the amount of times they need to deal with the overcharged weapons
that they find most problematic. As such, there is no strategy that will work
best for the majority of groups.

In the sections that follow we will talk a bit about each of the aspects
that are different (or simply more problematic) in Heroic mode.

11.2.1. Conveyor Belt

The first mentions must be made about how to handle the north-western
conveyor belt. The idea is the same as in Normal mode, but since the DPS
requirements are higher, you will almost certainly need to use 2 DPS players in 10-man and 4 or 5 in
25-man if you are to kill weapons in time (unless your DPS players' gear is
extremely good). Players who go up on the conveyor belt should save their DPS
cooldowns for the weapons, instead of using them on Blackfuse before going to
the belt.

We would like to note that it is possible for Hunters to go up on the
conveyor belt without going through the pipes. If a Hunter stands on top of a
pipe, with their back to the conveyor belt, and then jumps up and uses
Disengage, they will end up on the conveyor belt. This is extremely
useful because doing so allows the same Hunter to go up on the belt for each
wave, entirely bypassing the limitations imposed by the
Pattern Recognition debuff.

11.2.2. Electromagnets

The Overcharged Electromagnets will move raid members and sawblades back
and forth, causing obvious positioning issues. There is not much to be said
here.

11.2.3. Crawler Mines

Dealing with Overcharged Crawler Mines is fairly simple. The large
Crawler Mines will need to be killed as quickly as possible, with using as
little crowd-control on them as possible (so as to have it available for the
subsequent small Crawler Mines). Since the mines do not all spawn at the same
time, you should not concern yourselves too much with grouping them up for
AoE attacks. Instead, simply treat them as single targets.

Unlike what we recommend for the Normal mode strategy (tanking Blackfuse on
the opposite side of the platform from where the Crawler Mines spawn), it may
prove beneficial to have him tanked on top of where the Crawler Mines spawn to
allow for cleaving damage on the mines.

11.2.4. Missile Turrets

As soon as the Missile Turrets from Overcharged Missile Turret start
spawning, your ranged DPS players should switch to them and kill them.
Naturally, everyone should make sure to avoid getting hit by the Shockwave
effects it creates.

11.2.5. Laser Turrets

The Overcharged Laser Turrets are by far the most problematic part of
the encounter.
While the Overcharged Laser Turret is fairly simple to deal with (do not stand
in any of the fire it causes), this ability has other implications. Namely,
for a good period of time before an Overcharged Laser Turret appears, you must
be careful not to cover the safe zones with other ground effects. In
particular, players must note kite non-Overcharged Laser Turret beams over
future safe areas, nor must sawblades be placed there.

11.2.6. Automated Shredders

Given the fact that the Automated Shredders deal more damage in Heroic
mode, their Overload ability can become quite problematic. For the
3rd and 4th Overloads of any given Shredder, you should use raid or personal
cooldowns to ensure that everyone survives. In the event that your tank has
still not killed the Shredder by the time of the 5th Overload, the damage will
be extremely high, so strong cooldowns are mandatory (although you will still
probably wipe if this happens).